The exercise text says "Depending on which 50 people you selected, your estimate could be a bit above or a bit below the true population proportion of 0.26. In general, though, the sample proportion turns out to be a pretty good estimate of the true population proportion, and you were able to get it by sampling less than 1% of the population."
(1) I thought that the true populatin parameter was "0.2".
(2) As far as I'm concerned, we sampled 50 out of 100,000 observations. Isn't that way below "1% of the population"? You're statement is not wrong, if I'm right, but I think the 1% overstate the true dimension of the sample size compared to the population size.